Upgrade to 5GB from 3GB Unlimited was a downgrade

As I have been on a 3GB Unlimited data package, my internet access was sometimes strangled but I hardly ever had to purchase data top up. I decided that after 2 or more years, it was time for an upgrade. I called up MTN who happily Upgraded my current package to 5GB data. Little did I realise that it was not unlimited and that it was the BIGGEST mistake made. I was running out of data every few days and was spending hundreds topping up data bundles. I thought there must be something wrong and when I called the help desk they insisted I was using the data, as I had just purchased an Iphone I thought perhaps that was using all the data. When I called again the following month, I was still having problems and was told the 5GB hadn't been allocated to me correctly and that was why I was running out of data. When I continued running out of data, I called Somayya Akhalwaya and she advised me that the reason I was running out all the time was because the package was not Unlimited - whereas the previous package was unlimited and it had taken me almost 3 months to get this info I could no longer revert back to old package instead MTN want to charge me to leave!!